Electric and so-called “hybrid-electric” vehicles store electrical power in an electric power storage, such as a battery. The electric power is used by the vehicle to be converted into useful work, such as by powering electric motors that are connected to the vehicle's wheels. In these hybrid-electric vehicles, a combustion engine, such as a petrol or diesel engine rotates an electric generator that produces electric power, is stored in a battery for powering one or more electric motor(s). The electric power in electric and hybrid-electric vehicles may also be generated using other means such as regenerative braking, which converts the energy dissipated during the braking and slowing down of the vehicle into electric energy for example.
The electric vehicle (EV), which lacks an independently fueled engine, relies on an external power source to provide the energy stored in the battery. The electric vehicle therefore includes a charging plug receptacle that allows a vehicle operator to couple the vehicle to a utility-grid connected electric circuit. Electrical power is transferred from the utility-grid connected electric circuit to the vehicle for charging or charging the batteries. A third type of vehicle, a so-called plug-in hybrid electric (“PHEV”) includes an engine for generating power during operation, but also incorporates a charging plug receptacle to allow charging the battery when the vehicle is not in use.